Bumping, because I've had a few things bothering me for a while now:
Independence guaranteed: If a country declares independence and wins whatever initial struggle it may have, it will, more likely than not, stay independent for the rest of the TL, whether it lasts another decade, century, or millennia. This is more true for countries present in OTL than otherwise, such as Belgium or Switzerland. The writer is probably going to keep said country independent as long as he or she can, "killing" it off only if the author runs out of things to say, which leads to...
Death by Ignorance: If an author knows very little about a country or group of people, he or she will make another country or group of people he or she knows more about conquer the area.
Natives Don't Exist: I think we're getting better about this, but it's still found in some TLs centered around colonization. According to this, early colonizers of the Americas will never encounter natives during their initial settling period, unless those natives are the Aztecs or are armed with guns. Later expansion across the West will never have this problem either, so that an ATL with Swedish colonization of North America will have absolutely no problem establishing trade posts and cities in the Dakotas, say. Furthermore, if natives are mentioned at all and are defeated just once, they will never be a problem ever again. This cliche applies equally well to Africa, and, to a lesser degree, the Indies.